Hooded exhaust vent



v United States Patent I [72] Inven r Monroe wexlel 3,-294,l 15 12/1966 Koenigsberg 251/65 Philadelphia, Pennsylvania l 21 1 pp No. 802,536 Primary ExammerMeyer Perlin Filed 1 Feb. 26, 1969 Attorney Edelson and Udell [45] Patented Nov. 24, 1970 Acme Manufacturing Company Philadelphia, Pennsylvania a corporation of Pennsylvania [73] Assignee [54] HOODED EXHAUST VENT ABSTRACT: An air venting apparatus for use with air discharge blowers, including an air discharge duct, a flap valve having a swingable valve plate movable by gravity to close the discharge end of the duct and one or more magnetic latches operative upon the valve plate to releasably retain the same in its duct closing position. Each latch includes a magnet, and a strike plate magnetically held to the magnet when the valve is closed, the strike plate being preferrably carried by the valve plate to minimize mass loading thereof. The magnetic holding force is chosen to be sufficient to hold the valve shut against pressure differentials developed by outside wind, but is also chosen to be inadequate to prevent opening of the valve against pressure differentials developed by the associated air discharge blower.

Patemed Nov. 24, 11970 15,11,945

Sheet 1 of 2 Arm/awn.

MONROE L.WEXLE.R/

noomzn EXHAUST VENT This invention relates to venting apparatus for use in the discharge or exhausting of air from the interior of a building to the outside atmosphere, and more particularly, relates to blower and fan actuated venting apparatus such as is utilized with laundry dryers, cooking ranges and ovens.

The gravity type of air venting apparatus presently in use utilizes what may be termed a flap valve which includes a pivotally mounted valve plate positioned on one side of a face plate and has an air discharge duct secured to and extending from the opposite side of the face plate. The valve plate is movable to open and close the discharge end of the duct, the flap valve being opened by the pressure of the blower impelled air and being closed by gravity when the blower is inoperative and no air is being discharged under pressure.

The gravity closure type flap valve, however, suffers from the disadvantage that it is highly susceptible to severe and annoyin'g valve chatter due to wind movement past the outside of the valve when the blower is inoperative. This chatter results from the fact that the wind movement creates a low pressure condition on the outside face of the valve plate by comparison with the pressure on the inside face of the valve plate. The pressure differential thus forces the valve plate to pivot partially open to permit pressure equalization. As soon as the pressure equalizes, which is very quickly, the valve plate drops back into closed position with an attendant seating noise and thereby again sets up a valve opening pressure differential. The cycle of course repeats rapidly, resulting in a chattering action until the wind dies.

Attempts have been made to overcome such undesirable chattering operation of the flap valves by use of weights and springs, but with unsatisfactory results. The weights and springs do not eliminate the noisy operation of the flap valves because the action of their closing force on the valve is weakest at precisely the time when the strongest closing force is needed, namely, when the valve is closed and the blower is inoperative. Not only is this so, but even worse, the closing force on the valve plate increases as the valve is progressively opened. Thus, the blower impelled air, in order to keep the valve open, must now also overcome the increased closing force of the weights and/or springs acting on the valve plate, and this reduces the air discharge efficiency of the utility. In summary, the spring and/or weight mechanisms provide minimum closing force when maximum is desired, and maximum closing force when minimum is desired.

The present invention provides an effective solution to the chattering problem in that it provides maximum closure force on the valve when the valve is closed, and no closure force whatever on the valve when the valve is open under the influence of blower impelled air. This is achieved by the novel use of a magnetic holding latch which takes advantage of the fact that substantially higher valve opening pressure differentials are developed by the blower impelled air than are developed even by severe wind conditions. The magnetic holding force of the latch is thus chosen to be sufficiently high to prevent valve opening due to wind conditions, but at the same time to be insufficient to prevent valve opening by blower impelled air. The magnetic structure is such that once the valve is open, the magnetic holding force drops substantially to zero and does not again become effective until the valve closes under gravity after the blower becomes inoperative. Additionally, the latched valve is effective in preventing birds from entering and nesting in the air discharge duct.

Accordingly, it is a primary object of the invention to provide a valved air venting apparatus with means effective to maintain its valve closed against the chatter producing effect of pressure differentials caused by outside wind gusts, while at the same time adding only such resistance to the initial opening of the valve as is readily overcome by the pressure of blower impelled air.

Another object of the invention is to provide venting apparatus as aforesaid which utilizes magnetic latch means disposed in operative relation to the flap valve to releasably retain the same in such closed position.

A further object of the invention as aforesaid is the incorporation of the magnetic latches into the valve structure so as to minimize the mass load on the valve plate and avoid the creation of lint catching projections.

The foregoing and other objects of the invention will appear more clearly hereinafter from an examination of the following specification and the accompanying drawings, wherein:

FIG. 1 is a perspective view of the venting apparatus of the present invention showing the novel magnetic latch for releasably retaining the flap valve in closed position against the face plate of the apparatus;

FIG. 2 is a front elevational view of the apparatus shown in FIG. 1 as taken along the lines 2-2 thereof with portions of the flap valve and of the hood partly broken away;

FIG. 3 is a bottom view of a portion of the apparatus shown in FIG. 2 as taken along the lines 3-3 thereof;

FIG. 4 is a sectional view of a portion of the apparatus shown in FIG. 2 as taken along the lines 4-4 thereof with the flap valve in full line closed position and in dotted line opened position;

FIG. 5 is a sectional view of the magnetic latch portion of the apparatus shown in FIG. 2 as taken along the lines 5-5 thereof;

FIG. 6 is a front elevational view of a modified form of the venting apparatus of the present invention with portions of the flap valve and of the hood partly broken away, this modified form having a pair of magnetic latches to yieldingly maintain the flap valve in closed position against the face plate of the apparatus;

FIG. 7 is a bottom view, partly in section, of a portion of the apparatus shown in FIG. 6 as taken along the lines 7- 7 thereof; .1

FIG. 8 is a side elevational view, partly in section, of the front end of the apparatus shown in FIG. 6 as taken along the lines 8-8 thereof with the flap valve in full line closed position and in dotted line opened position; and

FIG. 9 is a sectional view of one of the magnetic latches and adjoining portions of the apparatus shown in FIG. 6 as taken along the lines 9-9 thereof.

One embodiment in a venting apparatus of the present invention is shown in FIGS. 1 through 5 wherein there is illustrated, as a part thereof, a cylindrically shaped exhaust conduit or duct 10 having a free end 11 which, in the use of the apparatus, is positioned to extend inwardly through the outer wall of a building to the interior thereof wherein the said free end 11 of the duct 10 is connected by suitable means, not shown, to the exhaust outlet of an air blower which typically might be part of a home clothes dryer or be associated with an oven or range vent or the like. The other end 12 of the duct 10 is secured to and extends outwardly from an outer face or wall plate 13 of generally rectangular shape, which is positioned against the outer surface of the wall of the building through which the duct 10 extends. An interior finishing plate, not shown, of suitable outline, having an aperture therein to snugly fit over the duct 10 is positioned thereon so as to be flush against the inside surface of the building wall. The face plate 13 is provided with a suitable circular opening for receiving therein and for fastening the end 12 of the duct 10 thereto, the said end 12 of the duct 10 being flared as at 14 and being provided with a terminal bead 15 for defining therebetween the connection of the duct 10 to the plate 13, as appears in FIG. 4.

The apparatus is further provided with a swingable flap valve plate 16 the upper end 17 of which is hingedly suspended from the upper end of the face plate 13 on the side of the latter opposite to the duct 10, the valve plate 16 being movable about a horizontal axis and being of such dimensions as to close the opening of the duct 10 in the plate 13 when the valve plate 16is in its closed position, as appears in FIGS 1- A protective hood 18 is also provided, the hood being secured to the plate 13 along the vertical and top edges of the the plate wherein the valve plate 16 may move to limited opened position, as in FIG. 4.

The constructional details of the aforementioned apparatus are fully shown and described in my US. Pat. No. 3,l7l,343, issued March 2, 1965, to which reference is hereby made for a more complete description thereof. In the patented construction, the flap valve plate is gravity actuated to closed position when no air is being discharged therethrough and no means is provided to prevent the said flap valve plate from intermittent and chattering noise-making contact with the face plate as it moves to its closed position nor is any means provided to retain the valve plate in closed position against the action of the opening pressures thereon which may develop because of differential pressures resulting from differences in atmospheric conditions on both sides of the valve plate.

In order to releasably retain the valve plate 16 of the venting apparatus in its closed position and to positively close and hold the same closed, the apparatus is provided with one or more magnetic latches the cooperative portions of which, i.e., a strike plate and a magnet, are disposed respectively on the valve plate 16 and on the face plate 13. Extending downwardly from and secured to the central bottom edge portion of the valve plate 16 is an arm or tab member 19 of any desired magnetically susceptible metal, such as stainless steel, the tab 19 serving as the strike plate of a magnetic latch and being secured, in this instance, to the valve plate 16 by means of suitably disposed rivet 20 extending therethrough.

Secured to the hood side of the plate 13 in position to underlie the tab 19 and to be covered thereby when the valve plate 16 is in closed position, is a small circular cup 21 of any desired magnetically susceptible metal, such as stainless steel, and within which is disposed a disc-shaped magnet 22, which might suitably be a rubber composition magnet, the said cup and magnet being secured, in this instance, to the plate 13 by means of a suitably disposed nonmagnetic rivet 23 extending therethrough. It should be noted, FIG. 5, that the upper surfaces of magnet 22 and rivet 23 are below the level of the top of the cup 21 and that there is an air gap between the proximate surfaces of the magnet 22 and of the tab 19 when the valve plate 16 is in closed position. This gap provides good control of the magnetic holding force exerted on the strike plate through physical engagement of the plate with the perimetral edge of the open top of cup 21. Additionally, in closed valve position the cup 21 is closed by the strike plate 19 to protect the magnet 22 against exposure.

While magnet 22 is chosen so as to have sufficient force to positively hold the tab 19 thereto, as the valve plate 16 reaches its closed position under the influence of gravity, to thus positively close the valve 16 without any chattering thereof and to releasably retain the valve in closed position, such magnetic force is of a sufficiently low order of magnitude that it does not prevent opening of the magnetic latch and of the valve plate 16 when air is discharged through the duct and impinges upon the valve plate 16 from the associated air blower Furthermore, it should be noted, that as the valve plate 16 moves away from the magnet 22 and is in its opened position, the magnet 22 no longer exertsany closing effect upon the tab 19 and has no effect upon the resistance of valve plate 16 to the passage of air past the same. It may be noted that in this respect the magnetic latch differs sharply from the use of weights or springs to close and to maintain flap valves of venting apparatus in closed position. The closing forces exerted by weights and by springs are weakest when the flap valves are in closed condition and increase as the valves are moved toward their opened positions whereby the valves offer increased resistance to the continued opening thereof by the discharged air passing the same and thus reduce the efficiency of the venting apparatus by imposing a back-loading pressure upon the blower of the apparatus.

A second embodiment of the invention is shown in FIGS. 6 through 9, and while similar in principle to the embodiment of FIGS. 1 through 5, a difference resides in the use of a pair of magnetic latches in which the strike plates directly engage the magnets to releasably maintain the flap valve in closed condition.

In FIGS. 6 through 9 there are seen a duct 10' and a face plate 13' to which the duct 10 is secured by means of the flare l4 and the bead 15 formed therein, together with a hood l8 and a valve plate 16. The primed elements are similar in structure and function to their previously described unprimed counterparts.

The flap valve plate 16' is shaped somewhat differently from the valve plate 16 and has no tab corresponding to the tab 19 fastened thereto. Instead, the lower portion of valve plate 16' is widened and squared to extend over and in contact with a pair of spaced disc-shaped magnets 24, 24 secured to the hood side of the plate 13 between the bead l5 and lower edge of the plate, the magnets being positioned on the plate by means of suitable rivets 25 extending therethrough.

The flap valve plate 16' is made of any desired magnetically susceptible metal, such as stainless steel, and functions, with respect to the magnets 24-24 in the manner in which the tab 19 of the valve plate 16 functions with respect to the magnet 22, except that while the inner surface of flap valve plate 16' is in direct contact with the magnets 24-24 to provide a pair of magnetic latches, the tab 19 is in spaced relation to the magnet 22 and in direct contact with its cup 21. It should be noted that in both embodiments the magnet structures are located to be out of the airstream to avoid trapping dust, fuzz and lint.

While it is preferred that the magnets 24-24 be secured to the face plate of the vent apparatus as shown in order to minimize the mass loading on the valve plate 16, it will be understood that in certain instances it may be desirable to secure such magnets to the valve plate 16, in which case the face plate 13 would be formed of, or be provided in the regions of its engagements with the magnets 24-24 with overlaps of magnetically susceptible materialv It will be understood that the present invention is susceptible of various other changes and modifications which may be made from time to time without departing from the general principles or real spirit thereof, and accordingly it is intended to claim the same broadly, as well as specifically, as indicated by the appended claims.

I claim:

1. An air venting apparatus for coupling to the exhaust outlet of an air blower, which blower when actuated is operative to discharge air through its exhaust outlet into the venting apparatus for discharge therefrom into an outside atmosphere, said venting apparatus comprising in combination,

a. an air duct having an inlet couplable to the air blower exhaust outlet and terminating at and discharging air through a face plate at a discharge outlet;

b. a hingedly suspended movable valve plate operatively coupled to said air discharge outlet to form therewith an openable and closable valve, said valve plate having an inside face and an outside face, said valve plate inside face presenting toward said face plate and closing the said air discharge outlet by closing movement against said face plate to thereby close said valve in the absence of blower impelled air moving through said air discharge outlet, and said valve plate outside face communicating with and being subject to the pressure of the aforesaid outside atmosphere; and

c. magnetic latch means operative in the absence of blower impelled air against the said inside face of said valve plate to hold said valve plate in its closed valve position regardless of variations in pressure to which the said outside face of said valve plate may be subjected, said magnetic latch means comprising at least one magnet and an associated strike plate of magnetically susceptible material engageable with and separable from said magnet, one of said magnet and strike plate being secured to said face plate out of the airstream and the other being carried by said valve plate, said magnetic latch means being inoperative to hold said valve closed in the presence of blower impelled air against the said inside face of said valve plate.

2. Air venting apparatus as defined in claim I wherein said magnetic latch means further includes a cup comprising magnetically susceptible material within which said magnet is disposed in magnetic circuit therewith, said cup confining the magnetic flux to a controlled path whereby magnetic interaction with said strike plate is rendered substantially negligible until said valve plate is substantially in its closed valve position, said strike plate being bendable toward and away from.

Disclaimer 3,541,945.Mom'0e L. Wewler, Philadelphia, Pa. HOODED EXHAUST VENT. Patent dated Nov. 24, 1970. Disclaimer filed Mar. 15, 1971, by the assignee, Acme M anufcwtun'ng Company. Hereby enters this disclaimer to claim 1 of said patent.

[Oflicial Gazette June 15, 1.971.] 

